[2.2.1] Bad width for toolbar buttons on IE8 in "EmulateIE7" mode

[2.2.1] Bad width for toolbar buttons on IE8 in "EmulateIE7" mode

When using toolbar buttons with text in a page with containing

HTML Code:

<meta http-equiv=\"X-UA-Compatible\" content=\"IE=EmulateIE7\" />

to force IE8 in compatibility mode, buttons with text have w additional width at the left and right (the exact amount seems the depends on the button's text), see attached screenshot. Buttons have the correct width when the compatibility mode is activated manually on a page without the X-UA-Compatible meta tag.